1. Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea
2. Department of Orthodontics, Pusan National University Hospital, Busan, Korea
3. Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH, USA
4. Department of Orthodontics, Saint Louis University, Saint Louis, Mo, USA
5. Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Korea